Metal-on-Metal and Other Bearing Trends Among Fellows of the AAOS

To determine what the trends for the use of total hip arthroplasty bearings have been in the United States and how the Food and Drug Administration (FDA) warning on the use of metal on metal bearings have affected surgeon’s decisions concerning their use, a survey was performed on the fellows of the American Academy of Orthopaedic Surgeons (AAOS). Two thousand randomly selected practicing fellows were invited to take part in the AAOS 2010 survey. Of those invited, 170 (8.5 % response rate) completed the survey. Confidence interval (CI) values at 95 % were provided for each survey item. There were no significant differences between invitees and respondents in terms of practice setting and gender. The majority of respondents (79.2 %) match their patients’ function/activity to the bearing surface used in total hip arthroplasty (THA). Respondents mostly use peer reviewed publications (92.9 %), and personal experience (81.7 %) when making a decision on bearing use in THA. Almost 80 % of the respondents indicated that their hospitals do not limit their choice of implants. Cross-linked polyethylene has been the most used type of bearing surface before 2010 (74.80 %) and currently (78.62 %). Metal-on-metal and ceramic-on-ceramic use decreased; however, there are no significant differences between the uses of all types of bearings before 2010 and currently. Given the current debated issues, 75.6 % of respondents are less likely to use metal-on-metal bearing in the future; 22 % are not affected. The majority of respondents (70.3 %) indicated that ceramic-on-ceramic bearing have fewer wear particles. More than half (56.7 %) indicated that metal-on-metal (MoM) has the longest survivorship. This survey indicated that surgeons responded that their use of MoM bearings will likely decrease in the future but the numbers in this survey show no significant difference in their use before and after the FDA warning for MoM bearings. The survey does show that most surgeons believe that they will have less choice as directed by their hospital or insurance companies in their bearing use in the near future due to health economics and the efforts to decrease cost. Only time will tell if surgeons who indicate the use of MoM will decrease over time actually comes to fruition or if the use of MoM will continue at its current rate. This survey indicates that although the trend shows a decrease in their use, it was not statistically significant.

Keywords:

total hip arthroplasty, bearing surface, metal-on-metal

Author Information:

Urish, Kenneth L.Dept. of Orthopaedics and Rehabilitation, Division of Musculoskeletal Sciences, College of Medicine, The Pennsylvania State Univ., Hershey, PA